/*
 * Created on 6 Feb 2007
 * Created by Allan Crooks
 * Copyright (C) Azureus Software, Inc, All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */
package org.gudy.azureus2.ui.common.util;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.Map;

import org.gudy.azureus2.core3.util.AEMonitor;
import org.gudy.azureus2.core3.util.Debug;
import org.gudy.azureus2.plugins.ui.menus.MenuItem;

/**
 * Similar to TableContextMenuManager - this keeps references to created menu items by plugins to be used by external code.
 * 
 * @author amc1
 */
public class MenuItemManager {

    private static MenuItemManager instance;

    private static AEMonitor class_mon = new AEMonitor("MenuManager");

    /*
     * Holds all the MenuItem objects. key = MENU_* type (see MenuManager in the plugin API) value = Map: key = menu key value = MenuItem object
     */
    private Map<String, Map<String, MenuItem>> items;

    private AEMonitor items_mon = new AEMonitor("MenuManager:items");

    private ArrayList<MenuItemManagerListener> listeners = new ArrayList<MenuItemManagerListener>(0);

    private MenuItemManager() {
        this.items = new HashMap<String, Map<String, MenuItem>>();
    }

    /**
     * Return the static MenuManager instance
     */
    public static MenuItemManager getInstance() {
        try {
            class_mon.enter();
            if (instance == null)
                instance = new MenuItemManager();
            return instance;
        } finally {
            class_mon.exit();
        }
    }

    public void addMenuItem(MenuItem item) {
        try {
            String name = item.getResourceKey();
            String sMenuID = item.getMenuID();
            try {
                this.items_mon.enter();
                Map<String, MenuItem> mTypes = this.items.get(sMenuID);
                if (mTypes == null) {
                    // LinkedHashMap to preserve order
                    mTypes = new LinkedHashMap<String, MenuItem>();
                    this.items.put(sMenuID, mTypes);
                }
                mTypes.put(name, item);

            } finally {
                this.items_mon.exit();
            }
        } catch (Exception e) {
            System.out.println("Error while adding Menu Item");
            Debug.printStackTrace(e);
        }
    }

    public void removeAllMenuItems(String sMenuID) {
        this.items.remove(sMenuID);
    }

    public void removeMenuItem(MenuItem item) {
        Map<String, MenuItem> menu_item_map = this.items.get(item.getMenuID());
        if (menu_item_map != null) {
            menu_item_map.remove(item.getResourceKey());
        }
    }

    public MenuItem[] getAllAsArray(String sMenuID) {
        if (sMenuID != null) {
            triggerMenuItemQuery(sMenuID);
        }
        Map<String, MenuItem> local_menu_item_map = this.items.get(sMenuID);
        Map<String, MenuItem> global_menu_item_map = this.items.get(null);
        if (local_menu_item_map == null && global_menu_item_map == null) {
            return new MenuItem[0];
        }

        if (sMenuID == null) {
            local_menu_item_map = null;
        }

        ArrayList<MenuItem> l = new ArrayList<MenuItem>();
        if (local_menu_item_map != null) {
            l.addAll(local_menu_item_map.values());
        }
        if (global_menu_item_map != null) {
            l.addAll(global_menu_item_map.values());
        }
        return l.toArray(new MenuItem[l.size()]);
    }

    public MenuItem[] getAllAsArray(String[] menu_ids) {
        ArrayList<MenuItem> l = new ArrayList<MenuItem>();
        for (int i = 0; i < menu_ids.length; i++) {
            if (menu_ids[i] != null) {
                triggerMenuItemQuery(menu_ids[i]);
            }
            addMenuItems(menu_ids[i], l);
        }
        addMenuItems(null, l);
        return l.toArray(new MenuItem[l.size()]);
    }

    private void addMenuItems(String menu_id, ArrayList<MenuItem> l) {
        Map<String, MenuItem> menu_map = this.items.get(menu_id);
        if (menu_map != null) {
            l.addAll(menu_map.values());
        }
    }

    public void addListener(MenuItemManagerListener l) {
        synchronized (listeners) {
            if (!listeners.contains(l)) {
                listeners.add(l);
            }
        }
    }

    public void removeListener(MenuItemManagerListener l) {
        synchronized (listeners) {
            listeners.remove(l);
        }
    }

    private void triggerMenuItemQuery(String id) {
        MenuItemManagerListener[] listenersArray;
        synchronized (listeners) {
            listenersArray = listeners.toArray(new MenuItemManagerListener[0]);
        }
        for (MenuItemManagerListener l : listenersArray) {
            try {
                l.queryForMenuItem(id);
            } catch (Exception e) {
                Debug.out(e);
            }
        }
    }

    public void triggerMenuItemCleanup(String id) {
        MenuItemManagerListener[] listenersArray;
        synchronized (listeners) {
            listenersArray = listeners.toArray(new MenuItemManagerListener[0]);
        }
        for (MenuItemManagerListener l : listenersArray) {
            try {
                l.cleanupMenuItem(id);
            } catch (Exception e) {
                Debug.out(e);
            }
        }
    }
}
